Costing run CK40N planned price1 vs moving average price

Hi,

I hava a material with the following data in Costing 2 view of material master:

Planned price 1 750,00 Planned price date 1 17.07.2012
Planned price 2 0,00 Planned price date 2
Planned price 3 0,00 Planned price date 3

Valuation Class R900 Valuation Category
VC: Sales order stk Proj. stk val. class
Price control V Current period 1 2013
Price Unit 1 Currency EUR
Moving price 1.000,00 Standard price 0,00

After a costing run (CK40N), system calculated 1000 as "Cost of goods manufactured".

Why system didn't use 750 (Planned price1) in this calculation?

If the program of costing uses planned price1 when a value exists in the field why in this case used 1000?

Thanks

Best regards